1. Field of the Invention
The present invention relates to an imaging apparatus.
2. Description of the Related Art
In recent years, a CMOS image sensor subjects a pixel signal to analog-digital conversion (hereinafter referred to as A/D conversion) in a sensor device. Here, a high-speed and high-resolution A/D conversion process technique is known. The technique of Japanese Patent Application Laid-Open No. 2007-281987 includes inputting an image signal into a plurality of comparators, comparing the image signal with reference signals having different time changes from each other, and synthesizing the count data of a reset level (hereinafter referred to as base signal) N of a pixel signal and an effective signal S, after S-N processing. Thereby, the technique can acquire the A/D conversion data with a large number of bits.